The present invention relates to detergent formulations.
It is well known that in hard water areas magnesium and calcium ions cause unsightly deposits on surfaces, for example, on glassware, ceramic plates, fine china and plastic and other hard surfaces; this is especially marked when such items are washed in dish washing machines. Similar precipitation problems also occur in laundry washing, these cause the fabric to become stiff and rough to the touch and give coloured fabrics a faded appearance. Since before the mid 1960""s, sodium tripolyphosphate (STPP) has been used in large quantities in most detergent formulations as a xe2x80x9cbuilderxe2x80x9d; that is an agent which is able to sequester positive cations such as magnesium and calcium in the washing solution and prevent them from depositing as salts (carbonate, silicate etc.) on the items being washed.
However, it is now known that the presence of phosphate, for example in the form of STPP, in lakes and rivers serves as a nutrient for algae growth and this results in a deterioration of water quality. These environmental concerns have lead to the voluntary reduction and, in some cases, a legislative ban on the use of STPP in detergent formulations. In consequence, phosphate-free alternatives have been developed. Typically, these phosphate-free systems are based on a combination of soda ash, citrate, silicates, perborates, enzymes or chlorine sources. Unfortunately, when removing or decreasing phosphate levels, the changes occurring in the end result of a washing process are more than those expected from the simple decrease in sequestration capacity of the detergent matrix. This stems from the multi-purpose capabilities of the STPP in the areas of emulsification of oily particles, stabilisation of solid soil suspension, peptisation of soil agglomerates, neutralisation of acid soils etc.; all key to obtaining an excellent wash end result. In an attempt to combat this problem, homopolymers and copolymers, for example, carboxylic acid polymers, are added to most of the commercial detergent formulations in current use. This is well documented in the prior art, see, for example, U.S. Pat. Nos. 4,711,740, 4,820,441, 5,552,078, 5,152,910, 4,046,707 and 5,160,630. However, since these polymers are non-biodegradable they must be used at low concentration which often imparts less than desirable protection against filming, on machine washed glassware and crockery, and encrustation and soil re-deposition on fabrics in laundry washing.
The problem addressed by the present invention, therefore, is to provide further detergent formulations which have good anti-filming performance characteristics when used in machine dishwashing detergents and good anti-encrustation and anti-deposition performance characteristics when used in laundry washing.
Accordingly, the present invention provides detergent formulations comprising at least one water soluble polymer or salt thereof bearing at least one phosphonate group. The invention also provides detergent formulations comprising at least one water soluble polymer comprising: 
wherein X is H, Na, K or A; and A is a polymer, copolymer, or water soluble salt thereof, comprising, one or more of the following monomers in polymerised form:
carboxylic acids of the formula 
wherein
R1 is H, OH, C1-C9 alkyl or alkoxy or acetoxy or acetate
R2 is H, C1-C3 alkyl or alkoxy, COOR3 
R3 is H, Na, K or C1-C1-C10 alkyl;
hydroxypropyl acrylate, propyl methacrylate, 2-acrylamido-2-propane sulphonic acid, sodium styrene sulphonate, sodium allylsulphonate, sodium methyl sulphonate, vinyl sulphonic acid, and salts thereof; acrylamide, methacrylamide, tert-butylacrylamide, (meth)acrylonitrile, styrene, vinyl acetate allyloxy-2-hydroxypropyl sulphonate and dialkylacrylamide.
Machine dish washing detergents and laundry detergents are also provided which comprise detergent formulations of the present invention.
The detergent formulations containing polymers with phosphonate functional groups according to the invention show a surprising enhancement in the filming performance in machine dishwashing, anti-encrustation and anti-deposition performance in fabric laundering when compared to corresponding polymers without phosphonate functional groups. The detergent formulations according to the invention may be in powder, liquid, granular, pellet or tablet form, and may also contain up to 90% by weight of sodium carbonate.
The water-soluble polymers used in the present invention preferably have a weight average molecular weight below 20,000. Advantageously the weight average molecular weight is from 1,000 to 20,000, preferably from 1,000 to 10,000 and most preferably from 1,000 to 5,000.
The polymer used in the formulations of the present invention may comprise monoethylenically unsaturated (C3-C7) mono-carboxylic acids such as acrylic acid and methacrylic acid, and monoethylenically unsaturated (C4-C8) di-carboxylic acids such as maleic acid and itaconic acid.
The amount of polymeric builder present in the detergent formulations of the invention is typically 0.1% to 6% by weight of the detergent formulation. Some or all of the polymeric builder may be phosphonate containing polymers. Conveniently, the detergent formulations of the present invention may additionally comprise up to 90% by weight of the detergent formulation of a water soluble builder such as alkaline carbonate or bicarbonate salt, silicates and zeolites for example.
Any methods to prepare phosphonate containing polymers may be employed to make the polymers used in the present invention; see, for example, U.S. Pat. Nos. 4,046707, 5,376,731, 5,077,361 and 5,294,686.
The invention also provides for the use of polymers comprising: 
wherein X is H, Na, K or A; wherein A is a polymer, copolymer, or water soluble salt thereof, comprising, one or more of the following monomers in polymerised form:
carboxylic acids of the formula: 
wherein:
R1 is H, OH, C1-C9 alkyl or alkoxy or acetoxy or acetate;
R2 is H, C1-C3 alkyl or alkoxy, COOR3 
R3 is H, Na, K or C1-C10 alkyl;
hydroxypropyl acrylate, propylmethacrylate, 2-acrylamido-2-propane sulphonic acid, sodium styrene sulphonate, sodium allylsulphonate, sodium methyl sulphonate, vinyl sulphonic acid, and salts thereof; acrylamide, methacrylamide, tert-butylacrylamide, (meth)acrylonitrile, styrene, vinyl acetate allyloxy-2-hydroxypropyl sulphonate and dialkylacrylamide, as some or all of the builder in detergent formulations.
The invention will now be further illustrated by the following Examples.
The anti-filming performance in dishwashing applications and the anti-encrustation and anti-soil deposition performance in laundry applications of polymers containing phosphonate groups was compared with that of similar polymers without the phosphonate groups using phosphate-free machine base formulations typical of those in current commercial use. The polymers were added to the base formulations at dosage levels of up to 6% by weight of the final detergent formulation (DF), as shown in Table I.